UMBC Center for Advanced Studies in Photonics Research (CASPR)
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The Center for Advanced Studies in Photonics Research (CASPR) fosters advanced photonics research and technology development in the areas of optical communications, optical sensing and devices, nanophotonics, biophotonics, and quantum optics in order to benefit government, industry and scientific progress.
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Item Large Third-Order Nonlinearities in Atomic Layer Deposition Grown Nitrogen-Enriched TiO₂ Nanoscale Films(IEEE, 2020-08) Kuis, Robinson; Gougousi, Theodosia; Basaldua, Isaac; Burkins, Paul; Kropp, Jaron A.; Johnson, Anthony M.Nonlinear refractive index, n₂, values as high as 1±.1x10⁻⁹ cm² /W were measured in atomic layer deposition (ALD) grown TiO₂ nanoscale films, using femtosecond thermally managed Z-scan. The several order of magnitude increase in n₂ is believed due to the incorporation of nitrogen during growth.Item Engineering of Large Third-Order Nonlinearities in Atomic Layer Deposition Grown Nitrogen-Enriched TiO₂(ACS Publications, 2019-10-17) Kuis, Robinson; Gougousi, Theodosia; Basaldua, Isaac; Burkins, Paul; Kropp, Jaron A.; Johnson, Anthony M.The third-order nonlinear optical properties of Nitrogen-enriched TiO₂ films deposited by Atomic Layer Deposition (ALD) at a temperature between 100 – 300°C on quartz substrates were studied using thermally managed Z-scan technique. TiO₂ oxide films prepared by Physical Vapor Deposition (PVD) at room temperature were used as control samples. The as-grown ALD films deposited at 150 – 300°C exhibited values for the nonlinear index of refraction, n₂, between 0.6x10ˉ¹¹ and 1x10ˉ⁹ cm²/W, which is 4–6 order larger than previously reported. Annealing the films, for 3 hours at 450°C in air, reduced the nonlinearities below the detection limit of the experimental setup. Similarly, as-grown 100°C ALD and PVD films did not produce a discernible Zscan trace. Composition analysis performed by x-ray photoelectrons spectroscopy (XPS) reveals the presence of Ti-O-N metallic bonds in the films that showed high nonlinear optical response. The presence of the metallic bonding gives the films deposited on Si (100) a golden color. These results demonstrate the possibility of a new class of thin-film nonlinear materials that their properties can be tailored by controlling the film composition.Item Where Does Work End and Home Life Begin?(IGI Global Disseminator of Knowledge, 2009) Berge, Zane L.; Bichy, Cassie; Grayson, Candice; Johnson, Anthony; Macadoff, Stephen; Nee, KathrynMany years ago, it was a commonly held belief that technology would improve industries and service professions, which means that people could work shorter hours and their employers would make just as much money. Essentially, this is the central myth of modern capitalism. Modern technologies are the shackles that bind today’s employees to their jobs long after they get home from work. Beginning in the 1990s, technology made working from home possible for a growing number of people. At first this was perceived as the era of great things to come. At home, many people had personal computers connected to their corporate network. It quickly became clear that telecommuting and the rapidly proliferating “electronic leash” of cell phones made work inescapable in the 24/7, on-demand work accessibility (Curry, 2003).Item Simulation of the Evolution of Information Content in Transcription Factor Binding Sites Using a Parallelized Genetic Algorithm(2011-07-30) Cornish, Joseph; Forder, Robert; Erill, Ivan; Gobbert, Matthias K.The analysis of transcription factor binding motifs may aid in understanding the process by which transcription factors recognize their binding sites. We wish to investigate the likelihood that transcription factors use correlation between positions instead of conservation of single positions as a mechanism for binding site recognition. We implement a genetic algorithm in parallel using a server-client organization to simulate the evolution of these binding sites. A performance analysis of the parallel algorithm showed significantly improved performance over the serial counterpart. The results of the simulation indicate that overall correlation is unlikely to be used in transcription factor binding site recognition.Item Rapid recombinant protein expression in cell-free extracts from human blood(Nature, 2018-06-22) Burgenson, David; Gurramkonda, Chandrasekhar; Pilli, Manohar; Ge, Xudong; Andar, Abhay; Kostov, Yordan; Tolosa, Leah; Rao, GovindSeveral groups have recently reported on the utility of cell-free expression systems to make therapeutic proteins, most of them employing CHO or E. coli cell-free extracts. Here, we propose an alternative that uses human blood derived leukocyte cell extracts for the expression of recombinant proteins. We demonstrate expression of nano luciferase (Nluc), Granulocyte-colony stimulating factor (G-CSF) and Erythropoietin (EPO) in cell-free leukocyte extracts within two hours. Human blood is readily available from donors and blood banks and leukocyte rich fractions are easy to obtain. The method described here demonstrates the ability to rapidly express recombinant proteins from human cell extracts that could provide the research community with a facile technology to make their target protein. Eventually, we envision that any recombinant protein can be produced from patient-supplied leukocytes, which can then be injected back into the patient. This approach could lead to an alternative model for personalized medicines and vaccines.Item Stability of cnoidal wave frequency combs in microresonators(OSA Publishing, 2018) Qi, Zhen; Wang, Shaokang; Jaramillo-Villegas, Jose A.; Qi, Minghao; Weiner, Andrew M.; D’Aguanno, Giuseppe; Menyuk, CurtisWe determine the regions in the parameter space of microresonators where cnoidal waves (Turing rolls) are stable. Solitons are included as a special limit. We identify conditions to efficiently obtain broadband frequency combs.